Microwave Surface Impedance Measurements of LiFeAs Single Crystals

Abstract

We report results of microwave surface impedance measurements of LiFeAs single crystals. The in-plane penetration depth depends on temperature exponentially at low temperatures, which strongly suggests that this material has the nodeless superconducting gap. The temperature dependence of the superfluid density indicates that LiFeAs is a multi-gap superconductor with at least two isotropic gaps. In addtion, the real part of the microwave conductivity exhibits a large enhancement below $T_{\mathrm{c}}$, indicating that the quasi-particle relaxation time, $\tau$, increases rapidly below $T_{\mathrm{c}}$. We believe that this enhancement is rather common to all superconductors where an inelastic scattering is dominant above $T_{\mathrm{c}}$, irrespective of the strength of the electron correlation.

arXiv comment13 pages, 3 figures

References in corpus (23)

• Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
• Magnetic Order versus superconductivity in the Iron-based layered La(O1-xFx)FeAs systems
• Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsO${}_{1-x}$F${}_x$}
• LaFeAsO${}_{1-x}$F${}_x$: A low carrier density superconductor near itinerant magnetism
• Observation of Fermi-surface-dependent nodeless superconducting gaps in Ba0.6K0.4Fe2As2
• LiFeAs: An Intrinsic FeAs-based Superconductor with Tc = 18K
• Electronic Structure and Doping in BaFe${}_2$As${}_2$ and LiFeAs: Density Functional Calculations
• Superconductivity without magnetism in LiFeAs
• Evolution from Itinerant Antiferromagnet to Unconventional Superconductor with Fluorine Doping in La(O_{1-x}F_{x})FeAs Revealed by ^{75}As and ^{139}La Nuclear Magnetic Resonance
• Momentum dependence of the superconducting gap in NdFeAsO1-xFx single crystals measured by angle resolved photoemission spectroscopy
• Superconductivity at 17 K in (Fe2P2)(Sr4Sc2O6): a new superconducting layered pnictide oxide with a thick perovskite oxide layer
• Microwave Penetration Depth and Quasiparticle Conductivity in PrFeAsO_1-y Single Crystals : Evidence for a Full-Gap Superconductor
• Strong electron correlations in the normal state of FeSe0.42Te0.58
• Universality in heavy-fermion systems with general degeneracy
• Microwave Surface-Impedance Measurements of the Magnetic Penetration Depth in Single Crystal Ba1-xKxFe2As2 Superconductors: Evidence for a Disorder-Dependent Superfluid Density
• Temperature dependent anisotropy of the penetration depth and coherence length in MgB$_2
• Strong-coupling Spin-singlet Superconductivity with Multiple Full Gaps in Hole-doped Ba${}_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$ Probed by Fe-NMR
• Weak superconducting pairing and a single isotropic energy gap in stoichiometric LiFeAs
• ${}^{75}$As NQR and NMR studies of superconductivity and electron correlations in iron arsenide Li${}_x$FeAs
• Hall effect in superconducting Fe(Se0.5Te0.5) thin films
• Enhancement of Superfluid Stiffness, Suppression of Superconducting T_c and Field-induced Magnetism in the Pnictide Superconductor LiFeAs
• Evidence for multiple gaps in specific heat of LiFeAs crystals
• Penetration depth anisotropy in two-band superconductors

Cited by in corpus (23)

• Superconductivity in Iron Compounds
• Functional Renormalization Group for multi-orbital Fermi Surface Instabilities
• Scanning Tunneling Microscopy/Spectroscopy of Vortices in LiFeAs
• Pauli-limiting effects in the upper critical fields of a clean LiFeAs single crystal
• Crossover from weak to strong pairing in unconventional superconductors
• Nodeless vs nodal order parameters in LiFeAs and LiFeP superconductors
• Superconductivity at 5.4 K in $\beta$-Bi${}_2$Pd
• The superconducting gaps in LiFeAs: Joint study of specific heat and ARPES
• The upper critical field and its anisotropy in LiFeAs
• Anomalous Temperature Dependence of the Superfluid Density Caused by Dirty-to-Clean Crossover in FeSe${}_{0.4}$Te${}_{0.6}$ Single Crystals
• Small anisotropy of the lower critical field and $s_{\pm }$-wave two-gap feature in single crystal LiFeAs
• Isotropic three-dimensional gap in the iron-arsenide superconductor LiFeAs from directional heat transport measurements
• Contrasts in electron correlations and inelastic scattering between LiFeAs and LiFeP revealed by charge transport
• Temperature-dependent spin-transport and current-induced torques in superconductor/ferromagnet heterostructures
• Microwave Surface Impedance Measurements of the Electronic State and Dissipation of Magnetic Vortices in Superconducting Iron-Based LiFeAs Single Crystals
• Investigation of the Superconducting Gap Structure in SrFe${}_2$(As${}_{0.7}$P${}_{0.3}$)${}_2$ by Magnetic Penetration Depth and Flux Flow Resistivity Analysis
• Raman Scattering Study of the Lattice Dynamics of Superconducting LiFeAs
• Electron and Superconducting Properties of the AFeAs (A= Li, Na) Family Alkali-Metal Pnictides: Current Stage of the Research (mini-review)
• Effect of Co Impurities on Superconductivity of FeSe0.4Te0.6 single crystals
• Optical properties of iron-based superconductor LiFeAs single crystal
• Investigation of LiFeAs by means of "Break-junction" Technique
• Probing the Order Parameter of Superconducting LiFeAs using Pb/LiFeAs and Au/LiFeAs Point-Contact Spectroscopy
• Specific Heat vs Field of LiFe1-xCuxAs